The present invention generally relates to a system and method for improved image registration for medial image analysis. Particularly, the present invention relates to a system and method for image registration using graph cuts algorithm to determine the minimum value of an energy function.
Medical diagnostic imaging systems encompass a variety of imaging modalities, such as x-ray systems, computerized tomography (CT) systems, ultrasound systems, electron beam tomography (EBT) systems, magnetic resonance (MR) systems, and the like. Medical diagnostic imaging systems generate images of an object, such as a patient, for example, through exposure to an energy source, such as x-rays passing through a patient, for example. The generated images may be used for many purposes. One example is medical diagnosis from 2-D and 3-D MR or CT images used by a doctor to investigate various organs of patients, including internal defects. Four-dimensional medical images containing information about 3-D volumes moving in time are also currently available. By comparing images over time, changes in internal structure or alignment may be determined. Fluid flow within an object may also be represented. The information gained from medical diagnostic imaging has applications in many fields, including medicine and manufacturing.
An example of a medical diagnostic imaging system is Picture Archival Communication Systems (PACS). PACS is a term for equipment and software that permits images, such as x-rays, ultrasound, CT, MRI, EBT, MR, or nuclear medicine for example, to be electronically acquired, stored and transmitted for viewing. Medical images from an exam may be viewed immediately, stored, or transmitted. The medical images may be viewed on diagnostic workstations, by users, for example radiologists. In addition to viewing the images, the user may also view patient information associated with the image, for example the name of the patient or the patient's sex.
Medical images, usually of substantially the same structure, may be acquired at different points in time. For example, a first set of medical images of a structure and a subsequent second set of medical images of the same structure may be acquired. The first set of images may be combined with the second set of images to create a composite medical image. Typically, the process of creating a composite medical image may be described as medical image registration. Medical image registration is a visualization tool that can significantly aid in the early detection of tumors and other diseases, and aid in improving the accuracy of diagnosis. For example, the medical image registration may illustrate information not apparent in the separate images. Medical image registration has been applied to the diagnosis of breast cancer, colon cancer, cardiac studies, wrist and other injuries, inflammatory diseases and different neurological disorders including brain tumors, Alzheimer's disease and schizophrenia.
Various medical image registration techniques are currently employed. However, current medical image registration techniques are typically time consuming. As a result, the time of a health care professional may not be used in an efficient manner. Additionally, current medical image registration techniques are typically inaccurate. The inaccurateness creates reliability problems for doctors and creates difficulty in determining an accurate diagnosis. Also, current medical image registration techniques are typically not robust. In general, current medical image registration techniques are sensitive to noise and initial conditions. The lack of robustness increases the rate of inaccuracies.